Answer:
See explanation
Explanation:
If the energy of the ground state E1 is known, then we need to measure the difference in energy between the energy levels E5 .and E1. We can obtain this by measuring the frequency or wavelength of a photon that is emitted when an electron moves from energy level E5 to E1.
From Bohr's model;
ΔE = E5 - E1
Hence;
E5 = ΔE + E1
Answer:
49.4 g Solution
Explanation:
There is some info missing. I think this is the original question.
<em>A chemistry student needs 20.0g of acetic acid for an experiment. He has 400.g available of a 40.5 % w/w solution of acetic acid in acetone. </em>
<em>
Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button. Round your answer to 3 significant digits.</em>
<em />
We have 400 g of solution and there are 40.5 g of solute (acetic acid) per 100 grams of solution. We can use this info to find the mass of acetic acid in the solution.
Since we only need 20.0 g of acetic acid, there is enough of it in the solution. The mass of solution that contains 20.0 g of solute is:
There are two big advantages of using molarity to express concentration. The first advantage is that it's easy and convenient to use because the solute may be measured in grams, converted into moles, and mixed with a volume.
The second advantage is that the sum of the molar concentrations is the total molar concentration. This permits calculations of density and ionic strength
Answer:
52 da
Step-by-step explanation:
Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.
The i<em>ntegrated rate law for a first-order reaction </em>is
ln([A₀]/[A] ) = kt
Data:
[A]₀ = 750 mg
[A] = 68 mg
t_ ½ = 15 da
Step 1. Calculate the value of the rate constant.
t_½ = ln2/k Multiply each side by k
kt_½ = ln2 Divide each side by t_½
k = ln2/t_½
= ln2/15
= 0.0462 da⁻¹
Step 2. Calculate the time
ln(750/68) = 0.0462t
ln11.0 = 0.0462t
2.40 = 0.0462t Divide each side by 0.0462
t = 52 da
Answer:
Genetic factors contributes to the formation of the dead zones is by their ability to expand their abilities that enables them to spread and contribute to the formation of the dead zones. These dead zones are made when the oxygen are low where it is necessarily important for the aquatic life, if the oxygen needed is depleted or too low, instead of supporting aquatic life, dead zones are created and factors contribute to these occurrences with their ability to expand.
Explanation:
